金嘴蝎尾蕉花部维管束系统的解剖学研究

Floral Vascular System Anatomy of Heliconia rostrata(Heliconiaceae)

利用石蜡切片技术对蝎尾蕉科代表植物金嘴蝎尾蕉(Heliconia rostrata Ruiz&Pavon)的花部维管束系统进行了解剖学研究。结果表明,心皮背束在延长部的基部分裂为内外2分支,内方分支与胎座维管束汇合后进入花柱,远轴面2枚外方分支在延长部的顶部分裂为2～4束进入远轴面2枚外轮雄蕊,而近轴面1枚外方分支则进入退化结构成为其中脉;隔膜束在延长部顶部亦分裂为3～5束,最终分别进入3枚内轮雄蕊;子房壁其它维管束最终进入花被片。本研究认为金嘴蝎尾蕉花部花瓣状退化结构与另外2枚外轮雄蕊具有完全相同的维管束系统来源,应属于雄蕊成员,且支持Kress关于蝎尾蕉科是姜群的姊妹群,区别于芭蕉群其它3科的观点。

The floral vascular system of Heliconia rostrata Ruiz Pavon were studied using paraffin section.Results showed that the carpellary dorsal bundles（cdbs） from the prolongation base were divided into two strands.A mixture of inner strands and placental bundles ran into the style.The two abaxial outer strands generated 2-4 branches and entered into the outer whorl at the two abaxial stamens,while the adaxial outer branch was the midrib of the staminode vasculature,which indicated its degenerate structure.After splitting into 3-5 strands at the top of the prolongation,the three parietal bundles（pbs） entered into the three stamens of the inner whorl and the remaining bundles of the ovary wall ultimately clustered into the perianth.Our results suggest that the degenerate structure with the outer androecial whorl is part of the androecium as it has the same origin of the vascular trace,Heliconiaceae is a sister family of the ginger group,different from the banana group.